Circadian clocks drive the daily patterns of behavior and physiology observed in most organisms. These internal clocks allow organisms to advantageously align their behavior to daily cycles in the environment such as light and temperature. The fruit fly Drosophila displays many robust, daily behavioral rhythms including discrete bouts of locomotor activity at dawn (i.e. morning activity) and dusk (i.e. evening activity). The molecular clocks that drive these daily activity bouts are found in approximately 150 circadian pacemaker neurons in the fly brain. Interestingly, the timing of the molecular clocks is synchronous between all pacemaker neurons, yet different subsets of these neurons appear to make quite different contributions to the regulation of morning vs. evening activity. It remains poorly understood how the molecular circadian clock drives daily rhythms in pacemaker neuron activity or how the activities of different groups of pacemaker neurons combine to produce complex behavioral output. The overall goal of this thesis is to characterize how different subsets of Drosophila pacemaker neurons contribute to daily behavioral regulation both individually and as a network. To examine daily patterns of neuronal activity in different groups of circadian clock neurons, we have established imaging methods using genetically encoded fluorescent sensors. For these sensors, changes in fluorescence levels correspond to changes in neuronal activity, thus allowing us to measure neuronal activity patterns in real-time and throughout the day. Using these tools, I have characterized the daily activity patterns of different groups of the clock neurons that agree with published rhythms in activity as assessed by patch-clamp electrophysiology and calcium imaging We have also used genetic and molecular approaches such as RNA interference (RNAi) to alter gene expression in a tissue-specific manner. These approaches allow us to manipulate the function of different groups of clock neurons and to determine how these manipulations affect rhythmic behavior and neuronal activity patterns. We have silenced different subsets of circadian pacemaker neurons using RNAi knockdown of the NARROW ABDOMEN (NA) sodium leak channel and identified a complex role for a subset of the posterior dorsal neurons 1 (DN1p) in regulating locomotor behavior. The DN1p are known to be involved in promoting morning behavior, and recent studies have shown that a subset of the DN1p regulate midday sleep bouts via downstream sleep regulating neurons. Our data suggest that the DN1p neurons likely suppress midday activity through inhibition of other circadian pacemaker neurons, and that this inhibitory role can be compensated for by light. Finally, we have also examined the intracellular mechanisms regulating circadian neuronal output. Rhythmic activity of the NA leak channel and its mammalian ortholog (NALCN) have been shown to contribute to daily excitability rhythms in circadian pacemaker neurons. We used temporally-restricted expression of RNAi and rescue constructs to identify a developmental requirement for the NA channel complex in Drosophila, and we demonstrate that channel complex proteins are very stable in the Drosophila brain. These data suggest that circadian regulation of the NA channel in adults may involve post-translational mechanisms that control activity and not just expression of the channel complex.

Doctor of Health Science / An investigation of clinical Abdominal Computed Tomography (CT)dose, and associated clinical diagnostic protocols, has been ndertaken. This research was carried out to study the pattern of CT dose from routine abdominal examinations in Malaysian practices. From this study it is hoped to establish a Dose Reference Level (DRL) to assist in optimising radiation dose for CT abdominal examination in Malaysia

Copies of author's previously published articles inserted. / Bibliography: leaves 187-209. / xiii, 209 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Documents the establishment of a reproducible model of carcinoma implanted into the abdominal wall of an immunocompetent Dark agouli rat to study the relationship between laparoscopy and the development of port site metastases. / Thesis (M.D.)--University of Adelaide, Dept. of Surgery, 1998?

Bien que les organes creux (intestins, etc.) puissent être lésés lors d'accidents automobiles, les recherches biomécaniques passées se sont principalement intéressées aux organes pleins. Deux axes de recherche ont été explorés dans cette étude : - le comportement mécanique du mésentère humain, qui est le principal moyen de fixité de l'intestin grêle, a été caractérisé lors d'essais de traction sur échantillons. Le mésentère s'est comporté comme un matériau anisotrope sensible à la vitesse de déformation. Des valeurs de raideur et déformation à rupture ont été proposées. - les effets des conditions aux limites entre organes sur les réponses interne et externe de l'abdomen ont été étudiés par simulation. Des modélisations permettant ou non le glissement entre un solide représentant les intestins, les organes pleins et la cavité abdominale ont été implémentées dans trois modèles éléments finis qui ont été soumis à des impacts correspondant à une étude de la littérature. Les relations force-déflexion, et les cinématiques internes et externes étaient très similaires pour les trois modèles. Les déformations prédites dans un mésentère très simplifié étaient supérieures aux déformations à rupture obtenues expérimentalement sur échantillons. Toutefois, aucune lésion du mésentère n'était décrite dans l'étude de référence. Ce résultat pourrait remettre en cause la représentation des intestins par un solide unique typiquement utilisée dans les modèles existants ainsi que celle du mésentère utilisée dans cette étude. En l'absence de données internes sur les organes et le mésentère lors d'un choc, il est difficile de savoir comment ces modélisations devraient évoluer.

There is a great challenge to deal with psychid taxonomy due to the sexual dimorphism and conservative morphology of male. The genus Eumeta is widely distributed among Asia, Australia and Africa, with taxa resembling each other in morphological aspects. This historical confusion was originated from misidentification of type specimen and difficulty of specimen vouchering. Previous studies also recorded Eumeta of Taiwan, but taxa still uncertain actually. In present study, reared specimens were used to acquire morphology of different development and larval case style, and corroborated each other with barcode of life. As the results, Eumeta minuscula and E. variegata were confirmed in Taiwan. A highly variation of male morphology with genitalia asymmetry were described. Additionally, the male 8th tergite and sternite were suggested valuable for species identification. Having examined the type series specimen and original description, 13 species distributed in orient were grouping. Except E. minuscula and E. crameri were smaller and identifiable, a mass of ambiguous species included E. variegata, E. maxima, E. layardi, E. japonica, E. pryeri, E. sikkima, E. wallacei, E. javanica, E. wallacei var. bougainvillea, E. formosicola and E. kiushiuana were defined as E. variegata species-complex, and then revised this complex mainly with Taiwanese specimens. Due to the morphological variety of whole examination involving with those of Taiwan, 8 species were treated as junior synonym of E. variegata, excluding E. japonica, E. javanica and E. kiushiuana that remain undetermined because the types have not examined. Preliminary result of molecular work also supported this treatment as well, except an individual of China (Yunnan) that more information is needed.

El presente trabajo tiene como finalidad mostrar la anestesia raquídea con bupivacaína pesada como una excelente alternativa en cirugías de abdomen bajo, sobretodo en cirugías de miembro inferior. Este estudio está basado en pacientes que fueron sometidos a esta técnica durante los meses de Junio a Agosto de 1996, año en que ingresó al país la bupivacaína pesada. Se realizó en la Sala de operaciones del tercer piso del Hospital Arzobispo Loayza. Se seleccionó 60 pacientes de ambos sexos con edades de 18 a 85 años y con una clasificación de ASA I, II y III, cuyos datos fueron vaciados a una ficha de recolección de datos. Los pacientes fueron premedicados con Midazolam intramuscular de acuerdo a edad y peso, y algunos fueron premedicados con fentanyl porque requerían analgesia, como lo es en los casos de fracturas. Se realizó una hidratación previa a todos los pacientes, con 500 a 700 cc. de solución salina. Luego se procedió a realizar la técnica con el paciente en decúbito lateral derecho o izquierdo, según comodidad del paciente. La punción se realizó con aguja espinal N° 26 con bisel de Quincke, con las medidas de asepsia, se administró 15mg. ó 20 mg de bupivacaína pesada; siendo el nivel de L3 - L4 en todos los casos. El resultado obtenido fue de una anestesia con un rápido bloqueo sensitivo (alrededor de los 40 segundos a un minuto), y un bloqueo motor completo que por historia va de 5 a 7 minutos. El nivel de analgesia alcanzado fue alrededor del dermatoma T10 y en algunos casos hasta T7; y su duración en el 65% de los casos fue entre dos a tres horas. La incidencia de las complicaciones fueron mínimas.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 158-162).

Doctor of Health Science / An investigation of clinical Abdominal Computed Tomography (CT)dose, and associated clinical diagnostic protocols, has been ndertaken. This research was carried out to study the pattern of CT dose from routine abdominal examinations in Malaysian practices. From this study it is hoped to establish a Dose Reference Level (DRL) to assist in optimising radiation dose for CT abdominal examination in Malaysia

Zugl.: Münster, Univ., Diss., 2007.

Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 135-138). Also available in electronic format on the Internet.